﻿/*!
    协议相关的创建，校验和解析接收的应用
*/
#include "protocol.h"
#include <QTime>
#include <QEventLoop>
#include <QRandomGenerator>

/** CRC table for the CRC-16. The poly is 0x8005 (x^16 + x^15 + x^2 + 1) */
static uint16_t const crc16_table[256] = {
    0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
    0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
    0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
    0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
    0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
    0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
    0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
    0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
    0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
    0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
    0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
    0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
    0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
    0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
    0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
    0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
    0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
    0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
    0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
    0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
    0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
    0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
    0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
    0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
    0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
    0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
    0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
    0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
    0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
    0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
    0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
    0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040
};

/*!
    生成上位机发送数据协议的函数实现
    具体结构:
    协议头 1Byte -- 0x5A
    数据长度 2Byte
    设备ID 1Byte
    数据编号 2Byte
    实际内部数据 数据长度-3
    奇偶校验位 2Byte
*/
int CProtocolInfo::CreateSendBuffer(uint8_t nId, uint16_t nSize, uint8_t *pStart, bool bWriteThrough)
{
    if(m_pTxBuffer != nullptr)
    {
        if(bWriteThrough == false)
        {
            uint16_t nTotalSize, nIndex;
            uint16_t nCrcVal;
            uint16_t random;
            uint16_t nSendSize;

            //生成随机数
            qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
            random = QRandomGenerator::global()->bounded(65536);
            m_nPacketId = random;

            nSendSize = nSize+3;

            nTotalSize = 0;
            m_pTxBuffer[nTotalSize++] = PROTOCOL_SEND_HEAD;
            m_pTxBuffer[nTotalSize++] = (uint8_t)(nSendSize>>8);
            m_pTxBuffer[nTotalSize++] = (uint8_t)(nSendSize&0xff);
            m_pTxBuffer[nTotalSize++] = nId;
            m_pTxBuffer[nTotalSize++] = (uint8_t)(random>>8);
            m_pTxBuffer[nTotalSize++] = (uint8_t)(random&0xff);

            if(nSize != 0 && pStart != NULL)
            {
                for(nIndex=0; nIndex<nSize; nIndex++)
                {
                    m_pTxBuffer[nTotalSize++] = *(pStart+nIndex);
                }
            }

            nCrcVal = CrcCalculate(&m_pTxBuffer[1], nTotalSize-1);
            m_pTxBuffer[nTotalSize++] = (uint8_t)(nCrcVal>>8);
            m_pTxBuffer[nTotalSize++] = (uint8_t)(nCrcVal&0xff);

            return nTotalSize;
         }
         else
         {
            memcpy(m_pTxBuffer, pStart, nSize);
            return nSize;
         }
    }
    else
        return 0;
}

/**
 * 函数声明模板
 *
 * @param   crc:	previous CRC value
 * @param   data:	data
 *
 * @return NULL
 */
static inline uint16_t crc16_byte(uint16_t crc, const uint8_t data)
{
    return (crc >> 8) ^ crc16_table[(crc ^ data) & 0xff];
}

/**
 * 函数声明模板
 *
 * @param   crc:	previous CRC value
 * @param   buffer:	data pointer
 * @param   len:	number of bytes in the buffer
 *
 * @return NULL
 */
uint16_t crc16(uint16_t crc, uint8_t const *buffer, uint16_t len)
{
    while (len--)
        crc = crc16_byte(crc, *buffer++);
    return crc;
}

/*!
    CRC16校验的代码实现
*/
uint16_t CProtocolInfo::CrcCalculate(uint8_t *pStart, int nSize)
{
    uint16_t nCrcOut;
    if(pStart == NULL || nSize == 0)
    {
        return 0;
    }

    nCrcOut = crc16(0xFFFF, pStart, nSize);
    return nCrcOut;
}

/*!
    接收数据并返回处理结果
*/
int CProtocolInfo::CheckReceiveData(bool IsSignalCheckHead)
{
    int nRead;
    int CrcRecv, CrcCacl;

    //回复的初始状态初始状态
    m_RxBufSize = 0;
    m_RxTimout = 0;
    m_RxDataSize = 0;

    do
    {
        if(m_RxBufSize == 0 && IsSignalCheckHead == false)
        {
            nRead = DeviceRead(&m_pRxBuffer[m_RxBufSize], 1);
            if(nRead > 0 && m_pRxBuffer[0] == PROTOCOL_RECV_HEAD)
            {
                m_RxBufSize++;
                m_RxTimout = 0;
            }
            else
            {
                m_RxBufSize = 0;
                m_RxTimout++;
            }
        }

        if(m_RxBufSize > 0 || IsSignalCheckHead == true)
        {
            nRead = DeviceRead(&m_pRxBuffer[m_RxBufSize], m_MaxBufSize-m_RxBufSize);
            if(nRead > 0)
            {
                if(IsSignalCheckHead == true && m_pRxBuffer[0] != PROTOCOL_RECV_HEAD)
                {
                    m_RxBufSize = 0;
                    return RT_FAIL;
                }

                m_RxTimout = 0;
                m_RxBufSize += nRead;
                if(nRead >= PROTOCOL_RECV_HEAD_SIZE)
                {
                    int nLen;

                    m_RxDataSize =  m_pRxBuffer[1]<<8 | m_pRxBuffer[2];
                    nLen = m_RxDataSize + PROTOCOL_RECV_HEAD_SIZE + PROTOCOL_CRC_SIZE;
                    if(m_RxBufSize >= nLen)
                    {
                        /*计算head后到CRC尾之前的所有数据的CRC值*/
                        CrcRecv = (m_pRxBuffer[nLen-2]<<8) + m_pRxBuffer[nLen-1];
                        CrcCacl = CrcCalculate(&m_pRxBuffer[1], nLen-PROTOCOL_CRC_SIZE-1);
                        if(CrcRecv == CrcCacl)
                        {
                            #if TEST_DEBUG == 1
                            qDebug()<<"Protocol.cpp:Receive Ok";
                            #endif
                            break;
                        }
                        else
                        {
                            qDebug()<<QString("CRC err, Recv:%1, Cacl:%2").arg(CrcRecv, CrcCacl);
                            return RT_CRC_ERROR;
                        }
                    }
                }
            }
            else
            {
                m_RxTimout++;
            }
        }

        if(m_RxTimout != 0)
        {
            QThread::msleep(1);
            if(m_RxTimout > PROTOCOL_TIMEOUT)
            {
               qDebug()<<QString("Receive timeout");
               return RT_TIMEOUT;
            }
        }
    }while(1);

    return RT_OK;
}
